Mahachai is a fishing village, but also has an historic fort that was built and provisioned in the early 19th century when there was concern that Vietnam might be aggressive.
A well-known aspect of the Mahachai railway station is the every-day presence of a market that encroaches onto the track and has to be partially dismantled every time a train arrives or departs.
The trip between Bangkok and Mahachai is through the swampy river delta, and there are a couple of stops in tiny, laid-back villages.
If you want to continue by rail, after Mahachai, it is necessary to take a ferry over the river to the terminus of another section of single-track rail.
How to get there:
1. BTS [skytrain] to Wongwian Yai station
2. Short walk from BTS to Wongwian terminal on the Mahachai surface rail line
3. 1 hour rail journey to Mahachai [20baht round-trip].